Cacheback: Speculative Decoding With Nothing But Cache

Zhiyao Ma, In Gim, Lin Zhong


Abstract
We present Cacheback Decoding, a training-free and model-agnostic speculative decoding method that exploits the locality in language to accelerate Large Language Model (LLM) inference.Cacheback leverages only Least Recently Used (LRU) cache tables of token n-grams to generate draft sequences.Cacheback achieves state-of-the-art performance among comparable methods despite its minimalist design, and its simplicity allows easy integration into existing systems.Cacheback also shows potential for fast adaptation to new domains.
Anthology ID:
2025.emnlp-main.1581
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
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Publisher:
Association for Computational Linguistics
Note:
Pages:
31067–31072
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URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1581/
DOI:
Bibkey:
Cite (ACL):
Zhiyao Ma, In Gim, and Lin Zhong. 2025. Cacheback: Speculative Decoding With Nothing But Cache. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 31067–31072, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Cacheback: Speculative Decoding With Nothing But Cache (Ma et al., EMNLP 2025)
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